Social innovation vs. cultural innovation

The term "social entrepreneur" has seen a lot of usage in recent years. Wikipedia defines a social entrepreneur as someone who "recognizes a social problem and uses entrepreneurial principles to organize, create and manage a venture to achieve social change". Many of PopTech's Social Innovation Fellows fall into this category.

A new, similar term has recently come into play: cultural entrepreneur. In a recent article by Courtney E. Martin and Lisa Witter published on Standford Social Innovation Review blog, the authors propose that cultural entrepreneurship be regarded as "social entrepreneurship's little sister."

From the article:

[W]e argue that cultural entrepreneurship is different than social entrepreneurship, because it is focused primarily on reimagining social roles and motivating new behaviors—often working with and in popular culture to reach the widest possible audience. Social entrepreneurs solve problems by disrupting existing systems, as microfinance has, or through breakthrough product design, like the solar powered lights from d.light design or Barefoot Power.

Cultural entrepreneurs, on the other hand, solve problems by disrupting belief systems—using television shows like Glee to initiate viewers into the disability or GLBTQ rights frameworks or the Twitter campaign #mensaythingstome, designed to expose anonymous misogyny online.

While it's true there are a plethora of new tools that enable a movement to bring its message to an intended audience, cultural entrepreneurship reads a bit like good old-fashioned activism.

What do you think? Has social entrepreneurship matured to the point where it's branching out its family tree, as the authors suggest? Or is cultural entrepreneurship just activism in a Tweet's clothing?